<div class="left-nav">
    <div id="side-nav">
        {volist name="list[0]" id="vo_father"}
        <ul id="nav">
            <li>
                <a href="javascript:;">
                    <i class="iconfont">&#xe723;</i>
                    <cite>{$vo_father.name}</cite>
                    <i class="iconfont nav_right">&#xe697;</i>
                </a>
                {notempty name="list[$vo_father.id]"}
                {volist name="list[$vo_father.id]" id="vo_son"}
                <ul class="sub-menu">
                    <li>
                        <a _href="{$vo_son.url}">
                            <i class="iconfont">&#xe6a7;</i>
                            <cite>{$vo_son.name}</cite>
                        </a>
                    </li >
                </ul>
                {/volist}
                {/notempty}
            </li>
        </ul>
        {/volist}
    </div>
</div>